Moscow planned to celebrated the annexation of huge swathes of Eastern Ukraine Friday but Putin’s party was wrecked by a lightning counter-attack that may have trapped thousands of his men in a key city supposedly now part of Russia. Ukrainian sources claimed that the strategic city of Lyman, which has served as a Russian military hub in Donetsk, has been encircled and supply lines cut. “Lyman! The operation to encircle the Russian group is at the stage of completion,” said Ukrainian lawmaker Oleksiy Goncharenko on Friday. The claim could not be independently verified but, if confirmed, it would be one...